Fuel supply piping arrangement structure for motorcycle

Abstract

A fuel supply piping arrangement structure includes an internal combustion engine, an air cleaner attached to a seat rail, an intake air passage connecting the internal combustion engine to the air cleaner, and a pair of fuel injection valves attached, on downstream upstream sides, respectively, to an intake system including the air cleaner and the intake air passage. Fuel supply piping having one end connected to a fuel tank, and another end side connected to each of the fuel injection valves. Joint portions connected to the fuel supply piping are oriented to one side in a vehicle width direction. Connector portions of the fuel supply piping connected to the joint portions are oriented to another side in the vehicle width direction toward the joint portions. The fuel supply piping disposed along the intake system and connected to the fuel injection valves from the one side in the vehicle width direction.

The invention claimed is: 
     
       1. A fuel supply piping arrangement structure for a motorcycle, said fuel supply piping arrangement structure comprising:
 an internal combustion engine attached to a main frame; 
 an air cleaner attached to a seat rail; 
 an intake air passage connecting the internal combustion engine to the air cleaner; 
 an intake system comprising the air cleaner and the intake air passage; 
 a first fuel injection valve attached on a downstream side of the intake system; 
 a second fuel injection valve attached on an upstream side of the intake system; and 
 fuel supply piping having one end connected to a fuel tank disposed on the main frame, and having another end side connected to each of the fuel injection valves, 
 wherein respective joint portions of the first and second fuel injection valves are connected to the fuel supply piping and oriented to a first side of the fuel supply piping in a vehicle width direction, 
 connector portions of the fuel supply piping are connected to the first and second joint portions and oriented to another side in the vehicle width direction toward the joint portions, and 
 the fuel supply piping is disposed along the intake system and connected to the first and second fuel injection valves at the first side in the vehicle width direction. 
 
     
     
       2. The fuel supply piping arrangement structure for the motorcycle according to  claim 1 ,
 wherein the connector portions are formed by a T-shaped joint connected to the first fuel injection valve and an L-shaped joint connected to the second fuel injection valve, and 
 respective connection portions from the T-shaped joint and the L-shaped joint are oriented toward the joint portions. 
 
     
     
       3. The fuel supply piping arrangement structure for the motorcycle according to  claim 1 ,
 wherein the fuel supply piping is disposed on an opposite side of the intake system in the vehicle width direction from a throttle pulley opening and closing a throttle valve provided in the intake air passage. 
 
     
     
       4. The fuel supply piping arrangement structure for the motorcycle according to  claim 1 , further comprising:
 a cross member that couples a left frame to a right frame; and 
 a rear cushion unit having one end attached to the cross member, 
 wherein the intake system is positioned so as to pass, in a forward-rearward direction, a central portion in the vehicle width direction above the cross member, 
 the first and second fuel injection valves are attached on a center line of the intake system, the center line of the intake system extending longitudinally, and 
 the fuel supply piping is attached so as to be offset to one side in the vehicle width direction with respect to the intake air passage, and is disposed between the left and right frames. 
 
     
     
       5. The fuel supply piping arrangement structure for the motorcycle according to  claim 1 ,
 wherein the one end of the fuel supply piping is connected to a fuel pump attached to a lower portion within the fuel tank, and a position of the fuel supply piping is regulated by a part of the fuel tank via an elastic member. 
 
     
     
       6. The fuel supply piping arrangement structure for the motorcycle according to  claim 1 ,
 wherein the second fuel injection valve is attached to an air cleaner case forming the air cleaner, and a positioning portion positioning the fuel supply piping is formed in the air cleaner case. 
 
     
     
       7. The fuel supply piping arrangement structure for the motorcycle according to  claim 6 ,
 wherein a protective cover covers the second fuel injection valve from above, and 
 the fuel supply piping is held between the protective cover and the positioning portion of the air cleaner case.